The present invention relates generally to brakes for motor vehicles, and more particularly to an electromechanical parking brake.
A brake system for a motor vehicle, and in particular an automotive vehicle, functionally reduces the speed of the vehicle or maintains the vehicle in a rest position. Various types of brake systems are commonly used in automotive vehicles, including hydraulic, anti-lock or xe2x80x9cABS,xe2x80x9d and electric or xe2x80x9cbrake by wire.xe2x80x9d In a hydraulic brake system, hydraulic fluid transfers energy from a brake pedal to one or more brake pads for slowing down or stopping rotation of a wheel of the vehicle. In an electric brake system, the hydraulic fluid is eliminated. Instead, the application and release of the brake pads is controlled by an electromechanical brake such as an electric caliper.
It is desirable to equip any motor vehicle with a parking brake. To date, however, no fully satisfactory electromechanical parking brake for an electric brake system has been proposed.
The present invention is an electric caliper comprising a motor having a shaft, and a gear rotatable with the shaft and having at least one tooth projecting therefrom. A plunger is disposed on the shaft, and has at least one socket engagable with a corresponding tooth on the gear. A magnet disposed proximate the plunger is adapted to draw the plunger in a first axial direction, and a solenoid yoke disposed proximate the plunger is adapted to selectively draw the plunger in a second axial direction.
Accordingly, it is an object of the present invention to provide an electric caliper of the type described above with a parking brake feature that is relatively simple and inexpensive to manufacture.
Another object of the present invention is to provide an electric caliper of the type described above with a minimum of moving parts.
Still another object of the present invention is to provide an electric caliper of the type described above that is relatively insensitive to fatigue.
Still another object of the present invention is to provide an electric caliper of the type described above in which a permanent wheel braking force can be achieved without continuous electrical energization of the brake.
These and other features and advantages of the invention will become further apparent from the following detailed description of the presently preferred embodiments, read in conjunction with the accompanying drawings. The detailed description and drawings are merely illustrative of the invention rather than limiting, the scope of the invention being defined by the appended claims and equivalents thereof.